Definition of Epic:
Epics (aka epic stories) are large user stories that would thus be difficult to estimate or to complete in a single iteration. Epics are typically lower priority and are waiting be broken down into smaller stories.
Use of Epics:
Epics are usually placeholders for new ideas that have not been fully developed. Epics are common when developing the initial product backlog and they should eventually be broken down into more manageable user stories so that the requirements of a story become more narrowly defined.
Benefits of Epics:
- Great as placeholders for large requirements.
- Gives a big-picture view of user stories.